Comparison of Advanced Visual Field Defects Measured with the Tübingen Mobile Campimeter and the Octopus 101 Perimeter

Abstract

To compare the results of advanced visual field defects (VFD) measured with the conventional reference perimeter Octopus 101 (O-101) and the new portable Tübingen Mobile Campimeter (TMC). Thirty-seven subjects (18 to 75 years), 13 with advanced arcuate scotomas, 12 with VFD respecting vertical meridians, 6 with concentric constriction and 6 healthy controls were included. First examination was with O-101: grid 30 degrees -NO, 192 stimuli, 10 cd/m(2) background luminance, stimulus size: Goldmann III (26'); second examination was with TMC: 84 stimuli (subset of grid 30 degrees -NO), stimulus size 34', stimulus luminance 320-370 cd/m(2), background luminance 8-20 cd/m(2). Pointwise accuracy (proportion of concordant locations), sensitivity, and specificity were estimated into 95% confidence intervals (CI) by averaging individual logits. Examination durations were compared. TMC results are highly concordant with O-101 results for all defect classes. For the entire sample, the percentage of discordant points (perceived with TMC but not with O-101) among all discordant points was 35% (CI: 30% to 40%). Analyzed by VFD pattern, accuracy was highest in healthy controls scotomas (97.9%; CI: 97% to 98.5%) and lowest in arcuate scotomas (80.6 %; CI: 77.3% to 83.5%). Sensitivity was highest in concentric constriction (94.5%; CI: 82.9% to 98.4%) and lowest in healthy controls (59.1%; CI: 26.3% to 85.3%). Specificity was highest in healthy controls (98.1%; CI: 96.6% to 98.9%) and lowest in concentric constriction (77.4%; CI: 62.1% to 87.7%). Mean examination time was 4.6 minutes (TMC) and 9.8 minutes (O-101). The results indicate that the TMC is a feasible device for detection of VFD.